Power supplies and power converters are used in a variety of electronic systems. Electrical power is generally transmitted over long distances as an alternating current (AC) signal. The AC signal is divided and metered as desired for each business or home location, and is often converted to direct current (DC) for use with individual electronic devices or components. Modern electronic systems often employ devices or components designed to operate using different DC voltages. Accordingly, different DC-DC converters, or a DC-DC converter that supports a wide range of output voltages, are needed for such systems.
There are many different DC-DC converter topologies. The available topologies differ with regard to the components used, the amount of power handled, the input voltage(s), the output voltage(s), efficiency, reliability, size and/or other characteristics. Some ongoing innovation efforts for DC-DC converters involve improving efficiency (reducing losses). Two example sources of losses in DC-DC converters are switching losses and conduction losses. An ideal efficiency control scheme would be able to monitor the load current and instantaneously adjust switching parameters and/or the amount of current conveyed per switch cycle. This ideal efficiency control scheme is not possible due to detection/response delays and/or other imperfections. Also, DC-DC converter topology differences result in incompatibilities when applying the efficiency control scheme for one DC-DC converter topology to another DC-DC converter topology. For example; efficiency control schemes for two-level converter topologies are not adequate for multi-level (3 or more) converter topologies.